Fair Value Measurements (Details 1) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Assets:
Assets	$ 4,410
Liabilities:
Total liabilities	9,281	$ 10,049
Rochester Royalty Obligation [Member]
Liabilities:
Derivative fair value of derivative liability		9,287
Other Derivative Instrument [Member]
Assets:
Fair value of derivative asset	614
Liabilities:
Derivative fair value of derivative liability	4	762
Equity Securities [Member]
Assets:
Equity securities	3,796	4,488
Fair Value, Inputs, Level 1 [Member]
Assets:
Assets	3,517
Liabilities:
Total liabilities	0	0
Fair Value, Inputs, Level 1 [Member] | Rochester Royalty Obligation [Member]
Liabilities:
Derivative fair value of derivative liability		0
Fair Value, Inputs, Level 1 [Member] | Other Derivative Instrument [Member]
Assets:
Fair value of derivative asset	0
Liabilities:
Derivative fair value of derivative liability	0	0
Fair Value, Inputs, Level 1 [Member] | Equity Securities [Member]
Assets:
Equity securities	3,517	4,209
Fair Value, Inputs, Level 2 [Member]
Assets:
Assets	614
Liabilities:
Total liabilities	4	762
Fair Value, Inputs, Level 2 [Member] | Rochester Royalty Obligation [Member]
Liabilities:
Derivative fair value of derivative liability		0
Fair Value, Inputs, Level 2 [Member] | Other Derivative Instrument [Member]
Assets:
Fair value of derivative asset	614
Liabilities:
Derivative fair value of derivative liability	4	762
Fair Value, Inputs, Level 2 [Member] | Equity Securities [Member]
Assets:
Equity securities	0	0
Fair Value, Inputs, Level 3 [Member]
Assets:
Assets	279
Liabilities:
Total liabilities	9,277	9,287
Fair Value, Inputs, Level 3 [Member] | Rochester Royalty Obligation [Member]
Liabilities:
Derivative fair value of derivative liability		9,287
Fair Value, Inputs, Level 3 [Member] | Other Derivative Instrument [Member]
Assets:
Fair value of derivative asset	0
Liabilities:
Derivative fair value of derivative liability	0	0
Fair Value, Inputs, Level 3 [Member] | Equity Securities [Member]
Assets:
Equity securities	279	$ 279
Rochester Royalty Obligation [Member] | Royalty Obligation [Member]
Liabilities:
Derivative fair value of derivative liability	9,277
Rochester Royalty Obligation [Member] | Fair Value, Inputs, Level 1 [Member] | Royalty Obligation [Member]
Liabilities:
Derivative fair value of derivative liability	0
Rochester Royalty Obligation [Member] | Fair Value, Inputs, Level 2 [Member] | Royalty Obligation [Member]
Liabilities:
Derivative fair value of derivative liability	0
Rochester Royalty Obligation [Member] | Fair Value, Inputs, Level 3 [Member] | Royalty Obligation [Member]
Liabilities:
Derivative fair value of derivative liability	$ 9,277